Sound location device



H. RAABER ET AL SOUND LOCATION DEVICE Aug. 2, 1932.

Filed May 7, 1931 lllllll/ Pated Aug. z, 1932 determined by Aployed for th1s purpose diier, as far as' the angle of altitude is concerned, from the actual Y angle of altitude of the source of sound as determined by optical means, the said anglel UNITED STATES PATENT OFFICE maxaman. mi. rnrscnnma, :GNAz new, AND ERNST mcHwALnEn, or

vmmm, aus'rnu, AssIGNons To AcTIENGEsELLscHArT c. r. Gonnz' ormscnn ANsTALT Ac'rrova sroLncNosT x. r. oonnz onion Usramor BaA'nsmvA, czEcHosLovAxm, A conrm or czncnostovaxm BOUND LOCATION DEVICE l Application led May 7, 1931, Serial No.

The directions for incoming sound rays the apparatus usually emof altitude as determined by acoustical means being l'always smaller than the actual angles Vof Valtitude of the source of sound. The

differences between the angles of altitude as determined by the two) methods are the greater the smaller is the angle of altitude, and the eater is the vertical height of the source o sound above thehorizon. The said differences are due to the fact, that the velocit of propagation of sound in the air depen s to a notable extent of thetempera'- ture of the air while the influence of the air pressure on this velocity is comparatively *very small. vThe velocities of the propagation of sound in air at different temperatures are in the ratio of the square roots of the absolute temperatures of the air, that is to say centigrades.

@zx/t1 273 02 t2 -I- 273 the temperatures tf and t2 being measured Vin Now as horizontal strata of air may be assumed to be the strata of equal temperature, the temperature t of each of the v said horizontal strata may be determined from the temperature: toat the ground and Y the vertical height h of the same above the 'of sound, the rays of sound become curved V'which in the case of horizontally mcomlng sound rays result inthe greatest differences,

ground and the temperature di'erence 2=O.'0047 C. per'meter difference in height by the known formula t=t 'Eh. Owlng to vthe fact` that the rays of sound pass obliquely from each ofthe said horizontal strata into those next below them having a higher temperature and a higher velocity of propagation between altitude angles determined acousti- Acally and altitude angles determined opticallyof one and the same source of sound.

. In the case of verticall incoming sound ra s there-are no such d1 erences owlng` tot e fact that the ra s of-` sound pass perpendicularly through t e various strata of |air and 535,792, and in German-y Hay 17, 1980.

hence there is no refraction of the rays of sound. s

The object of the present invention is to determine mechanically from the given or estimated height of the source of sound above the horizon and from the altitude angle of the incoming rays of sound theactual angle of altitude of they source of sound and to transmit` this actual angle of altitude to other instruments such as telescopes, search lights, gun laying devices or the like.

With this object in view the present invention substantially consists in that the movements of rotation of the sound rays receiver around a horizontal axis are transmitted by a suitable gearing to the altitude angle indlcator of the source of sound in such a manner that the angle between the altitude indlcat-ed by the said indicator and the axis of the acoustic sound receiver has its maximum value when the last named axis is horizontal, .the said maximum value being adjustable in accordance with the vertical height of the source of sound above the horizon and with the temperature at the ground, the said angle decreasing at a redet-ermined rate as the altitude angle indlcated by the said indicator and being reduced to zero when the incoming sound rays are vertical. y s

In the annexed drawing two embodiments ,of our'present invention are shown by way of example. t v

v Fig. 1 is a side yelevation of the Virst'embodiment,

Fig. 2 is a detail illustrating the second embodiment. f

On a vertical shaft 1, Fig. 1, the bearing 2 for the horizontal shaft 3 of the sound receiver is rotatably mounted. On this horizontal shaft 3 is rotatably mounted the frame 4 of the sound receiver 5, 5 which -in the position shown in full lines is adjusted for horizontally incoming sound rays. Fast on the said frame is the actuating lever 6 which carries a stud 6a engaging in the position of the parts shown in full lines in to a suitable curved slot in an arm 7 rotatably mounted on a journal pin 8 carried by the biurcated end of a link 10 rotatably mounted ona journal pin -9 which is secured to the bearing 2 and parallel to the shaft 3. In the bifurcated part of the link10 a second bolt 11 is rotatably .dotted lines. Y the centre of the journal pin 8 is at 81 andy the centre of the stud 6a is at 6111.

mounted and provided with a transverse bore which encloses the smooth neck 12 of a screw provided with the thread 12a and a knurled disc 12b which thus is prevented from moving axially relatively to the bolt 11. The screw thread 12a engages into a female thread cut into the transverse bore of a bolt 13 rotatably mounted in the bifurcated .end 7a of the arm 7. To the bifurcated end 7a is secured a pointer arm 14', the pointer mark 14a of which moves along an exchangeable scale secured to the link 10 and concentric to the journal pin 8. By turning the knurled disc 12b the pointer mark 14a may be adjusted in accordance with the vertical height of the sound source above the horizon and with the temperature at the ground. l

Owin to the downwardly convex curvature of e svound rays in the position for horizontally incoming rays of sound shown in full lines the source of sound is actually at an angle of altitude p above the horizon and inthe direction of the line connecting the centres of journal pins 8 and 9 as is indicated by the position of the pointer 15 secured to the link 10 on the scale 16 secured to the bearing 2. The position ofthe arm 7 and the curvature of the slot therein are empirically determined in such, a manner` that the angle p of altitude of the source of sound located at a given or estimated height pass through the horizontal strata of air perpendieularly thereto, and hence do not undergo any change of direction by refraction, the said diierence must be reduced to zero as is seen in Fig. 1, which shows the corresponding position of the arts of the apparatus in In tiliis position of the parts As the connecting line of the centres of the shaft 3 and stud 6a gives the direction of the incoming rays of sound and the connecting line of the centres of the journal pins 8 and 9, and in the position shown in dotted-.lines Aof the journal pins 81 and 9, gives the direction to the actual position of the source of sound, therefore from the vertical positionof the directions 3, 6a1` and 9, 81 follows the angle of A altitude of 90 of the actual position of the source of sound.

Instead of the rotatably and adjustably mounted slotted arm 7 also a table of curves 71 connected to the link 10 might be used as shown in Fig. 2, on cwhich curve table curves are drawn which are computed for different temperatures at the ground and for different heights of the source of sound above the horizon. A pointer 6b on the actuating lever 6 is then substituted for the stud 6a. using the apparatus an attendant permanently adjusts the pointer 6b by operating the journal pin 8 provided with a handle on that curve of the curve table 71 which corresponds to the temperature at the ground after the curve table has been adjusted in accordance with the estimated height of the source of sound.

' What we claim is:

When l 1. A device for determining the direction 0I sound rays incoming from an overground sound rays emitting source comprising sound receivers, a frame carrying the said sound' to the horizontal' in accordancel with the height of the said sound rays emitting source above the horizon and with the temperature at the ground for the horizontal position of the acoustic axes ofthe said sound receivers" and means for operatively connecting the said frame with the said pointer, whereby the dif- .ference between the angle indicated by the said pointer and the angle of inclination of the acoustic axes of the said .sound receiver to the horizon 1s decreased following a predetermined law as the angle of inclination of the acoustic axes to the saidsound receivers tothe horizonrincreases from 0 to 90 and becomes zero when the last named angle becomesv 90. A

. 2.y A device for determining the direction of sound rays incoming from an overground sound rays emitting source comprising sound receivers', a frame carrying the said sound receivers, a horizontal shaft on which the said frame is rotatably mounted, a ointer for .indicating the actual angle ofV altitude of the said sound rays emitting source, means for -operatively lconnecting the said frame with the said pointer, these last named-means comprising an actuating lever rigidl connected at one end to the said frame, a 1in pivoted in the stationary structure of the apparatus 'and carrying at its pivoted end the said pointer,

the ground, and a stud on the outer end of f the said actuating link engaging into the curved slot in the said arm, wherebyv the difference between the angle indicated by the said pointer and the angle of inclination of the acoustic axes of the said sound receiver to the horizon is decreased, following a predetermined law7 as the angle of inclination of the acoustic axes to the said sound receiv- 5 ers to the horizon increases from 0o to 90 and becomes zero when the last named angle becomes 90.

3. A device for determining the direction of sound rays incoming 'from an overground ,0 sound rays emitting source comprising sound receivers, a frame carrying the said sound receivers, a horizontal shaft on Which the said frame is rotatably mounted, a pointer for indicating the actual angle of altitude of the ,5 said sound rays emitting source, means for operatively connecting the said frame with the said pointer, these last named means comprising an actuating lever rigidly connected at one end to the said frame, a link pivoted :o in the stationary structure of the apparatus and carrying at its pivotcd end the Said pointer and a plate carried by the said link the other end of the said actuating lever being adapted to move along any of the said curves :5 whereby the difference between the angle indicated by the said pointer and the angle of inclination of the acoustic axes lof the said sound receiver to the horizon is decreased following a predetermined law, as the angle of m inclination of the acoustic axes to the said vsound receivers to the horizon increases from (lo to 90o and becomes zero when the last named angle becomes 90.

In testimony whereof We aflix our signa- ;5 tures.

HA NS RAABER. KARL PETSCHENIG. IGNAZ PECHAN. ERNST EICHWALDER. 

